We recommend avoiding sections 104, 105, 122, 123, 408 and 428 for concerts. These sections are on the side of the stage or even behind.
The stage for a concert at Toyota Center is pushed back towards the end of the court, which is somewhat unusual for concerts in a basketball arena. This means that the head-on seats in the Upper Level (sections 415-421) are pretty far away. When buying in these sections, make sure you get a low row. There is a significant difference between row 1 and row 12.
Otherwise, Sections 112-115 will give you a head-on view, but you will still want to choose low rows. Comfortable seating can be found in the mid-rows of 109 and 118, while sitting in the lettered sections (A-F) will get you as close as possible, but you might have trouble seeing over people.